SEOUL (BLOOMBERG) - South Korea's President Moon Jae-in shook up his security team and appointed veterans in North Korea relations after Kim Jung Un's regime blew up a joint liaison office that once served as a symbol of his rapprochement towards Pyongyang.

Moon named Park Jie-won as the new head of the National Intelligence Service, his office said on Friday (July 3). Park helped broker the first inter-Korea summit 20 years ago when he was the chief of staff to former South Korean President Kim Dae-Jung and last year met Kim Yo Jong, the sister of North Korea's current leader at Panmunjom truce village, which straddles the border between the two Koreas.

Before North Korea detonated explosives in the US$15 million (S$21 million) facility paid for by South Korea and located in the North Korean border city of Kaesong, Kim Yo Jong said it was "high time" to break ties with South Korea, blaming Moon for not living up to promises he made in three summits with North Korea's leader Kim Jong Un that led to the set up of the liaison office.

The act of destruction, which a Moon spokesman denounced as "reckless", appeared to be part of a calculated gamble to try to force the South Korean president to break with the US and support sanctions relief for North Korea. The result was to literally blow up the most concrete achievement of Moon's decades-long drive to establish a lasting peace with his country's greatest foe.

Park told Bloomberg in an interview last month before the blast that North Korea fears US military supremacy, adding it wouldn't dare to start an all-out war in the Korean Peninsula.

He said reviving inter-Korea relations was a key task and that Kim Yo Jong plays a "pivotal role" in ensuring regime continuity.

"Unlike his predecessors, Kim Jong Un did not have enough time to solidify his political foundation before he got put into office," Park said. There is an urgent need within the North Korean regime to make Kim Yo Jong the "second-in-command" in case of an emergency since Kim Jong Un's children are "too young for that job", he said.

Moon also appointed Lee In-young, a ruling party lawmaker, as his new unification minister after his previous point person for North Korea resigned in the wake of the liaison office destruction.